Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
  • F25B47/006—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass for preventing frost
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B30/00—Heat pumps
  • F25B30/02—Heat pumps of the compression type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B40/00—Subcoolers, desuperheaters or superheaters
  • F25B40/02—Subcoolers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B41/00—Fluid-circulation arrangements
  • F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
  • F25B41/24—Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
  • F25B5/02—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in parallel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2309/00—Gas cycle refrigeration machines
  • F25B2309/06—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
  • F25B2309/061—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide with cycle highest pressure above the supercritical pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2347/00—Details for preventing or removing deposits or corrosion
  • F25B2347/02—Details of defrosting cycles
  • F25B2347/021—Alternate defrosting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2500/00—Problems to be solved
  • F25B2500/18—Optimization, e.g. high integration of refrigeration components

Definitions

• the present invention relates to the field of heat pumps.
• the invention more particularly relates to a method for optimizing the operation of a heat pump installation, in which the cycle fluid undercooled by the defrosting of a heat exchanger makes it possible to improve the efficiency of the installation.
• the invention also relates to an improved performance heat pump installation operating continuously.
• a heat pump captures thermal energy from an external environment or more generally from a source of heat called a cold source to restore it in a heating circuit, water circulating in this circuit , usually inside a building.
• a heat pump conventionally comprises a compressor, a condenser for supplying heat, an expander preparing the vaporization reaction by lowering the liquid pressure (to provide a low pressure liquid to the evaporator) and an evaporator.
• the evaporator generally consists of a heat exchanger in which the liquid refrigerant is vaporized by the heat extracted from the cold source.
• the coefficient of performance COP of a heat pump is defined as the ratio between the heat output delivered at the condenser and the work supplied. This work corresponds to the electric power consumed by the engine to move the compression system, also called "power absorbed".
• the coefficient of performance is often much lower than 3 for heat pumps operating in environments where the outside temperature is for example below 0 ° C.
• the evaporator which draws heat from the cold source, will therefore be subjected to very low temperatures.
• the present invention therefore aims to overcome one or more of the disadvantages of the prior art by proposing a heat pump installation recovering a maximum of energy so as to increase its coefficient of performance, and providing heat continuously all defrosting part of the installation when necessary.
• the invention relates to a heat pump installation operating from a cold source, comprising a circuit provided with at least one compressor, a condenser, expansion means, and at least one evaporator, a cycle fluid circulating in the circuit, the condenser being cooled by a fluid to be heated, characterized in that it comprises:
• At least two exchanger systems each composed of two fluidically and thermally linked disjoint heat exchange zones, the first exchange zone fulfilling the function of subcooling the cycle and de-icer fluid of the second exchange zone; , the latter performing the function of evaporator, the two exchanger systems being connected in parallel with the compressor - condenser assembly, on either side of at least two expansion means; - cycle of fluid flow means between the compressor assembly - condenser and exchange systems, as well as means of control and bypass means of the cycle fluid flow in the circuit for the operation of the installation according to either ; o a mode of alternating circulation of the cycle fluid in the defroster of a first exchanger system and then in the evaporator of the second exchanger system, o a simultaneous circulation mode in parallel, in each exchanger system, of the cycle fluid passing from first in the defroster and then in the evaporator.
• the installation composed of at least two exchanger systems makes it possible to carry out two optimizations within the framework of the operation of the installation.
• the cycle fluid passing through the first exchange zone of a first exchanger system transfers part of its heat energy to the latter in order to defrost it.
• this heat extraction makes it possible to cool the cycle fluid and for this purpose significantly increase the efficiency of the heat pump.
• the operating mode of the installation depends on the outside temperature, measured by thermometric measurement means controlled by a processor and software, actuating the control means according to the mode required for the corresponding outside temperature.
• the installation is designed to operate in different modes depending on the outside temperature, to ensure in all cases a continuous return of heat in the heating circuit.
• each exchanger system comprises:
• An exchange zone consisting of two sub-zones connected fluidically, the first sub-zone being positioned on a first side receiving a flow of air along a component parallel to the plane P in the exchanger system, the second sub-zone being positioned on a second side opposite said first side to bring out said air flow of the exchanger system; an exchange zone located between the two exchange zones and thermally connected to said exchange sub-zones.
• each exchanger in operation can receive a lateral air flow which will instantly cool in the area corresponding to the inlet and outlet sides of the air flow, on which there is the pipe of the evaporator in which circulates the cycle fluid.
• the zone in the center of the exchanger system heats and defrosts the zone by taking calories from the circulating fluid in the channel of the exchange zone.
• the second heat exchange zone surrounding the first heat exchange zone of each exchanger system, is of the finned tube type.
• each exchanger system comprises a radiator including the two exchange zones.
• each of said exchange zones extends over the entire height of a volume occupied by each exchange system.
• a further object of the invention is to provide a method of optimizing the operation of a heat pump installation, with improved efficiency and continuous heat exchange.
• the invention relates to a method for optimizing the operation of a heat pump installation operating from a cold source, comprising a circuit provided with at least one compressor, a condenser, means of relaxation, a cycle fluid flowing in the circuit, and at least one exchanger system performing an evaporator function, characterized in that it comprises: A step of transferring heat from the cycle fluid to a zone of an exchanger system different from that fulfilling the function of the evaporator, and having the effect of the subcooling of the cycle fluid and the defrosting of said exchanger system;
• the method comprises an alternative operating step, the cycle fluid not circulating in at least one of the evaporators by the combination of the timer means and the closure of at least one of the control means and bypass means, the cooling of the cycle fluid in the condenser and the operation of the compressor being continuous.
• the method comprises a step of simultaneous operation, the means of derivation of the cycle fluid flow being open and the control means being closed, allowing the heating of the cycle fluid in the two evaporators simultaneously.
• the method comprises a step of switching from one mode of operation to another when the external temperature, measured using at least one thermometric sensor, crosses a threshold value.
• the method comprises a step of sub-cooling the cycle fluid and de-icing of the exchanger systems only performed with the heat pump system's heat exchanger systems, without interrupting the upstream stage of cooling the fluid. cycle in the condenser.
• the cycle fluid is brought to a supercritical state in a part of the circuit.
• the cycle fluid after the relaxation phase of the cycle fluid, the latter is under pressure and temperature conditions such that the liquid and gaseous phases coexist.
• the warming of the cycle fluid in the evaporator will cause a gain in enthalpy at constant pressure and induce a gradual transition to the gaseous state of the fluid cycle.
• the method comprises a step of air circulation at the level of the exchanger systems reaching a speed of at least 2 m / s.
• the process comprises a step of evaporation in the exchange zone filling the evaporator function carried out at a maximum temperature of between -10 ° C. and -20 ° C.
• FIG. 1 illustrates a first embodiment of the invention
• FIG. 2 schematically shows a second embodiment of the invention
• FIG. 3 illustrates a sectional view along a plane P of a heat exchanger system
• FIG. 4 shows a sectional view of a heat pump installation in one embodiment of the invention
• FIGS. 5a, 5b and 5c illustrate two modes of alternative operation and a simultaneous mode of operation of the invention
• the taps (7, 7 ') are cut off and the control means (6) circulates the cycle fluid
• the taps (7, T) are cut off and the control means (6 ' ) circulates the cycle fluid
• the control means (6, 6') are closed and the branches (7, 7 ') open to circulate the cycle fluid.
• FIG. 6 represents a pressure / enthalpy diagram illustrating the contribution of the invention for the cycle of a heat pump
• the heat pump installation operates from a cold source (A).
• the installation conventionally comprising a circuit provided with at least one compressor (1), a condenser (2), at least two expander (3, 3 ') of at least two evaporators (4, 4') and at least two fans (5, 5 ').
• the cycle fluid circulating in the circuit may for example be a refrigerant known per se (refrigerant R1 34a, R22 or other similar fluid), may or may not be brought to a supercritical state.
• the condenser (2) is cooled by a fluid to be heated.
• the installation comprises at least two systems (1 2, 1 2 ') exchangers with the cycle fluid, each having a first zone (Z1, Z1') of heat exchange for cooling the cycle fluid and a second zone (Z2, Z2 ') for heat exchange surrounding the first (Z1, Z1') and for heating the cycle fluid.
• the second zone (Z2, Z2') corresponds to the evaporator (4, 4 ') of the circuit.
• fans (5, 5 ') with blades placed next to the exchanger systems (12, 12') generate a flow, for example circular or helical, passing right through the second zone (Z2, Z2 '). ) before exiting the box enclosing the fan-system exchanger assembly (5, 5 ', 1 2, 1 2').
• FIG. 4 shows a positioning of the fans (5, 5 ') at the side portions of a box (50) enclosing the components (1, 2, 12, 1 2', 3, 3 ', 4, 4') of the heat pump.
• Said box (FIG. 4, 50) is made with downward openings (51, 51 ') and below (52, 52') of the evaporators (4, 4 ') so that the air flow generated by the operation of the fans (5, 5 ') passing right through the second exchange zone (S2, Z2') of the exchanger systems (1 2, 1 2 '), between and out of the bottom of the box (50 ).
• the semi-enclosed space (53, 53 ') formed by the box and existing between each fan (5, 5 ') adjacent to an evaporator (4, 4') and the inner wall of the box (50) facing each fan (5, 5 '), allows when a fan (5, 5') ) is stopped to maintain the warm air heated by the cycle fluid in the top of the box (50), the density of the hot air is lower than that of the cold air, thus promotes the defrosting of the evaporator (4, 4 ') adjacent to the fan (5, 5') when stopped.
• the exchanger systems (12, 12 ') consist of two disjoint zones (Z1 and ⁇ , Z2 and Z2') of exchange in which the cycle fluid circulates. While the first zone (Z1, ⁇ ) of exchange, upstream of the expander (3, 3 ') in the direction of circulation, is traversed by the cycle fluid so as to heat the system (12, 12') exchanger the second zone (Z2, Z2 ') is passed downstream of the expander (3, 3') so that the evaporator (4, 4 ') heats the cycle fluid by extracting the heat from the cold source (AT).
• the supply of the evaporator (4, 4') after the outlet of the expander (3, 3 ') can be carried out with a distributor (E2, E2 ').
• a distributor E2, E2 '
• several circuits of the second exchange zone (Z2, Z2 ') are fed in parallel.
• the first zone (Z1, ⁇ ) constitutes a liquid / air exchanger.
• the system (12, 12 ') exchanger may comprise parallel fins aligned along an axis. These fins may be spaced apart by 3.2 mm or any other conventional gap.
• This system (12, 12 ') is distributed between a first side, common to a plurality of fins, of said second zone (Z2, Z2') which receives the flow of air entering the system (12, 12 ') exchanger in a component direction perpendicular to the axis of alignment of the fins or parallel to the fins, and a second common side to the same plurality of fins which is opposite the first side to bring out said air flow of the system ( 12, 12 ') exchanger.
• the pipe (21, 22) for receiving heat from the outgoing air flow forms all or part of the evaporator (4, 4 ') of the circuit and is positioned on either side of the sides of the system ( 12, 12 ') exchanger.
• the relative humidity percentage of the air flow used can be 90%.
• the Air circulation is carried out with a speed of between 1 and 2.5 m / s. for an inlet face in the exchanger system (12, 12 ') having an area of the order of 0.1 of 5 m 2 and more.
• the flow can also reach 15m 3 / s and even more for applications to industrial buildings.
• the system (12, 12 ') heat exchanger can also be devoid of fins and substantially comprise a smooth tube of stainless material, which makes it suitable for applications in corrosive atmospheres or loaded.
• the cycle fluid temperature (liquid) is 65 ° to the input (E1, ⁇ ) of a heat exchanger system (12, 12 '), the condensation temperature can be 67 ° vs.
• the cycle fluid leaving the first zone (Z1, ⁇ ) is cooled to a temperature of 8 ° C and is led via the outlet (S1, S1 ') to the expander (3, 3').
• each exchanger system (12, 12 ' ) may have a substantially constant height (h).
• the flow of air through such an entire surface of this volume generally parallelepiped, by entering through the second zone (Z2, Z2 ') exchange, i.e. by the first side.
• the height (h) is preferably greater than the depth (d) of the exchanger system (12, 12 '). This depth can be constant and of the order of 0.1 to 0.2 m while the surface of the inlet face of the air flow can correspond to 1 m 2 and more.
• the exchanger systems (12, 12 ') can advantageously be positioned vertically, as illustrated in FIG.
• each exchange zone (Z1 and ⁇ , Z2 and Z2 ') extends over the entire height (h) of the volume occupied by the exchanger system (12, 12').
• the thickness of the second exchange zone (Z2, Z2 ') where the evaporator (4, 4') is located can be comparable to or at least three times the thickness of the first zone (Z1, ⁇ ). ) exchange. Referring to Figure 3, there are four ranks to the realized exchange in the evaporator (4, 4 ') and a single place for the exchange of supercooling.
• the thickness of said second zone (Z2, Z2 ') is therefore much greater in this case than the thickness of the first exchange zone (Z1, Z1').
• the size of the exchanger system (12, 12 ') including the two zones (Z1 and ⁇ , Z2 and Z2') is variable depending on the powers envisaged.
• the total thickness of the exchange surface can be 180 mm for 5 rows: 4 rows for the evaporator (4, 4 ') and 1 row for the zone (Z1, Z1') forming the subcooler and the defroster.
• the pumping of calories to the cycle fluid in the second exchange zone (Z2, Z2 ') requires a surplus of thickness with respect to the calorie release operation performed in the zone (Z1, ⁇ ) of cooling.
• the size of the system (12, 12 ') exchanger of Figure 1 is 1000 x 1000 x 150. It should be noted here that this type of dimensioning with joining according to the largest section (1 m 2 in this case) of the subcooler of the exchanger (12, 12 ') against the evaporator (4, 4') makes it possible to optimize the defrosting.
• the circuit splits into at least two pipes (21, 22) at the outlet of the condenser (2), each of the pipes (21, 22) being connected to the inlet (E1, E1 ') of the first zone (Z1, Z1 ') of an exchanger system (12, 12').
• a control system (6, 6') of the circulation of the cycle fluid for example a solenoid valve, driven for example by software on the basis of temporal data and data collected for example using temperature sensors.
• the regulators (3, 3 ') and the control systems (6, 6') are external to the exchanger systems (12, 12 ').
• the pipes (21, 22) divide upstream of the inlet into the first exchange zone (Z1, ⁇ ) and merge downstream of the control means (6, 6 '), creating a derivation to avoid the circulation of the cycle fluid in the first zone (Z1, Z1 ') of exchange.
• the circulation of the cycle fluid in these branch circuits is controlled by bypass means (7, 7 '), which may be of the same type as the control means (6, 6').
• the inlet (E2, E2 ') and / or the outlet (S2, S2') of the evaporators can be placed at the same height level as the input (E1, E1 ') or the output (S1, S1') of the circuit part upstream of the regulators (3, 3 ') placed in the first zone (Z1, ⁇ ) exchange.
• cooling of the cycle fluid upstream of the expander (3, 3 ') results in subcooling with respect to a normal cycle (C1).
• the cycle (C2) obtained thus makes it possible to start the expansion with a fluid of less enthalpy.
• the effect of this subcooling is to obtain at the end of expansion (isenthalpic) an increase in the liquid level for the cycle fluid arriving in the evaporator (4, 4 '). Therefore, the capacity of the evaporator (4, 4 ') can be improved.
• the exchanger system (1 2, 1 2 ') may comprise a radiator including the two zones (Z1 and ⁇ , Z2 and Z2') of exchange.
• the cycle fluid is thus directed by the inlet (E1) in the first zone (Z1) of exchange of the first system (1 2) exchanger. H then occurs a calorie extraction from the cycle fluid to the first system (1 2) exchanger, with the combined effect of the subcooling of the cycle fluid and the defrosting of the evaporator (4) of the first exchanger system (12), the defrosting being all the more effective when the fan (5) is at the same time stopping, stopping the air circulation of the cold source (A), the hot air heated by the remaining cycle fluid further trapped in the box (50) near the exchanger (12) and the fan (5). ) the judgment promotes the defrosting of the evaporator (4) adjacent the fan (5) at standstill.
• the subcooled cycle fluid then exits the first zone (Z1) of the first exchanger system (12), moves from the outlet (S1) to the expander (3 ') and then enters the second zone ( ⁇ 2') exchange of the second system (12 ') heat exchanger, thereby enabling the cycle fluid to extract heat from the cold source (A) (the fan (5') operates and allows air circulation) and warm at the evaporator (4 ').
• the cycle fluid then flows from the outlet (S2 ') of the second zone ( ⁇ 2 ' ) of the second system (12 ') exchanger to the compressor (1), then from the compressor (1) to the condenser (2) where it is cooled.
• the cycle fluid is thus directed towards the inlet ( ⁇ 1 ') of the first zone ( ⁇ ) of the second system (12') heat exchanger, where it is subcooled while defrosting the second system (12 ') heat exchanger.
• the fan (5 ') is stopped, stopping the circulation of air at the system level (12') heat exchanger, the hot air heated by the remaining cycle fluid more trapped in the casing (50) near the exchanger (12 ') and the fan (5') at a standstill, favoring the defrosting of the evaporator (4 ') adjacent to the fan (5') at standstill.
• the sub-cooled cycle fluid then flows from the outlet (S1 ') of the first zone ( ⁇ ) of the second system (12') exchanger to the expander (3), before entering the second zone (Z2) d exchange of the first heat exchanger system, where it is cooled at the evaporator (4), the fan (5) operating and allowing the circulation of air and heat exchange between the cycle fluid and the cold source ( AT).
• the cycle fluid is then directs the output (S2) of the second zone (Z2) of the first system (12) exchanger to the compressor (1), then the compressor (1) to the condenser (2) where it is cooled.
• the state of the control systems (6, 6 ') is reversed again in order to de-ice again the first system (12) exchanger.
• This alternation of the state of the control means (6, 6 ') which is carried out for example by means of a timer, continues as long as the temperature of the outside air is below a threshold value, for example 7 "C, this temperature being measured for example by means of a thermometric sensor
• the bypass means (7, 7 ') are closed.
• the control means (6, 6 ') are closed and the bypass means (7, 7 ') are open.
• the cycle fluid thus circulates at the outlet of the condenser (2) in the two branch circuits leading to the two zones (Z2, Z2 ') of the systems (12, 12') exchangers, the cycle fluid not circulating in the two zones (Z1, ⁇ ) exchange systems (12, 12 ') exchangers.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Air Conditioning Control Device (AREA)
• Defrosting Systems (AREA)

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Family Applications (1)

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Cited By (4)

Citations (12)

Family Cites Families (1)

• 2011
  • 2011-08-04 FR FR1157148A patent/FR2978816B1/fr active Active
• 2012
  • 2012-07-30 WO PCT/EP2012/064902 patent/WO2013017572A1/fr unknown
  • 2012-07-30 EP EP12759659.1A patent/EP2739918B1/de not_active Not-in-force

Patent Citations (13)

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